Engineering Science and Materials Commons^™

Anisotropy Evolution Due To Surface Treatment On 3d-Printed Fused Deposition Modeling (Fdm) Of Acrylonitrile Butadiene Styrene (Abs), Blake E. Lozinski

Honors Undergraduate Theses

Purpose: This paper will present insight to the methodology and results of the experimental characterization of Acrylonitrile Butadiene Styrene (ABS) using Fused Deposition Modeling (FDM). The work in this research explored the effects of print orientation, surface treatment, and ultraviolet (UV) light degradation with the utilization of Digital Image Correlation (DIC) on ABS tensile specimens.

Design/methodology: ABS specimens were printed at three build orientations (flat (0 degrees), 45 degrees, and up-right (90 degrees)). Each of these specimens were treated with three different surface treatments including a control (acrylic paint, Cyanoacrylate, and Diglycidyl Bisphenol A) followed by exposure to UV light …

The Study Of Physiochemical Properties Of Cerium Oxide Nanoparticles And Its Application In Biosensors, Swetha Barkam

Electronic Theses and Dissertations

Biosensors continue to get smaller and faster with the advancement in nanotechnology through the use of nanomaterials to achieve high sensitivity and selectivity. However, the continued reliance on biomolecules or enzymes in the biosensor assembly poses the problem of reproducibility, storage and complexity. This dissertation research address some of the challenges by investigating the physiochemical properties of nanoparticles to understand its interaction with biological systems and develop enzyme free biosensors. In this study, we have demonstrated a novel strategy to integrate cerium oxide nanoparticles (CNPs) as an efficient transducer through rigorous screening for developing enzyme/label free biosensors for detecting analytes …

Assessment Of Potential Impacts To Surface And Subsurface Water Bodies Due To Longwall Mining, Christopher R. Newman, Zacharias Agioutantis, Gabriel Boede Jimenez Leon

Mining Engineering Faculty Publications

Ground movements due to longwall mining operations have the potential to damage the hydrological balance within as well as outside the mine permit area in the form of increased surface ponding and changes to hydrogeological properties. Recently, the Office of Surface Mining, Reclamation and Enforcement (OSMRE) in the USA, has completed a public comment period on a newly proposed rule for the protection of streams and groundwater from adverse impacts of surface and underground mining operations (80 FR 44435). With increased community and regulatory focus on mining operations and their potential to adversely affect streams and groundwater, now there is …

Quantification Of Re-Absorption And Re-Emission Processes To Determine Photon Recycling Efficiency In Perovskite Single Crystals, Yanjun Fang, Haotong Wei, Qingfeng Dong, Jinsong Huang

Department of Mechanical and Materials Engineering: Faculty Publications

Photon recycling, that is, iterative self-absorption and re-emission by the photoactive layer itself, has been speculated to contribute to the high open-circuit voltage in several types of high efficiency solar cells. For organic–inorganic halide perovskites that have yielded highly efficient photovoltaic devices, however, it remains unclear whether the photon recycling effect is significant enough to improve solar cell efficiency. Here we quantitatively evaluate the re-absorption and re-emission processes to determine photon recycling efficiency in hybrid perovskite with its single crystals by measuring the ratio of the re-emitted photons to the initially excited photons, which is realized by modulating their polarization …

Target Lesion Calcium Arc Influence The Performance Of Stenting, Pengfei Dong, Shengmao Lin, David L. Wilson, Hiram G. Bezerra, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Percutaneous coronary intervention (PCI) is the most common revascularization procedure, in which, fibrocalcific plaques are found in 17–35% of patients undergoing PCI [1]. Numbers will rise with population aging and prolonged statin treatment. Calcifications often lead to stent under expansion and strut malapposition, with increased risk of thrombosis and in-stent restenosis [2]. Presence of calcium strongly inhibits stent performance, a well-documented metric for outcome [3]. The goal of this work is to develop the finite element models for inspecting the influence of the calcium arc extent on the stenting outcomes, such as the stress and strain distribution within the plaque, …

Growth Mechanisms Of Multiscale, Mound-Like Surface Structures On Titanium By Femtosecond Laser Processing, Edwin Peng, Ryan Bell, Craig A. Zuhlke, Meiyu Wang, Dennis R. Alexander, George Gogos, Jeffrey E. Shield

Department of Mechanical and Materials Engineering: Faculty Publications

Femtosecond laser surface processing (FLSP) can be used to functionalize many surfaces, imparting specialized properties such as increased broadband optical absorption or superhydrophobicity/- hydrophilicity. In this study, the subsurface microstructure of a series of mound-like FLSP structures formed on commercially pure titanium using five combinations of laser fluence and cumulative pulse counts was studied. Using a dual beam Scanning Electron Microscope with a Focused Ion Beam, the subsurface microstructure for each FLSP structure type was revealed by cross-sectioning. The microstructure of the mounds formed using the lowest fluence value consists of the original Ti grains. This is evidence that preferential …

Dissipative Elastic Metamaterial With A Lowfrequency Passband, Yongquan Liu, Jianlin Yi, Zheng Li, Xianyue Su, Wenlong Li, Mehrdad Negahban

Department of Mechanical and Materials Engineering: Faculty Publications

We design and experimentally demonstrate a dissipative elastic metamaterial structure that functions as a bandpass filter with a low-frequency passband. The mechanism of dissipation in this structure is well described by a mass-spring-damper model that reveals that the imaginary part of the wavenumber is non-zero, even in the passband of dissipative metamaterials. This indicates that transmittance in this range can be low. A prototype for this viscoelastic metamaterial model is fabricated by 3D printing techniques using soft and hard acrylics as constituent materials. The transmittance of the printed metamaterial is measured and shows good agreement with theoretical predictions, demonstrating its …

Narrowband Nanocomposite Photodetector, Jinsong Huang, Fawen Guo, Liang Shen

Department of Mechanical and Materials Engineering: Faculty Publications

A photodetector includes an anode that is transparent or partially transparent to light, a cathode and an active layer disposed between the anode and the cathode. The active layer includes a nanocomposite material that has a polymer blended with nanoparticles or organic electron trapping particles. The photodetector has a low dark current when not illuminated by light and has a high conductivity when illuminated by light, in which the light passes the anode and is absorbed by the active layer. The active layer has a thickness selected such that the photodetector has a narrowband spectral response.

Role Of Copper Oxide Layer On Pool Boiling Performance With Femtosecond Laser Processed Surfaces, Corey Kruse, Edwin Peng, Craig Zuhlke, Jeff Shield, Dennis Alexander, Sidy Ndao, George Gogos

Department of Mechanical and Materials Engineering: Faculty Publications

Copper pool boiling surfaces are tested for pool boiling enhancement due to femtosecond laser surface processing (FLSP). FLSP creates self-organized micro/nanostructures on metallic surfaces and creates highly wetting and wicking surfaces with permanent surface features. In this study two series of samples were created. The first series consists of three flat FLSP copper surfaces with varying microstructures and the second series is an open microchannel configuration with laser processing over the horizontal surfaces of the microchannels. These microchannels range in height from 125 microns to 380 microns. Each of these surfaces were tested for pool boiling performance. It was found …

Compact Facility For Testing Steady And Transient Thermal Performance Of Building Walls, Aimee Byrne, Gerard Byrne, Anthony Robinson

Articles

Energy efficiency retrofit of buildings represents a key effort in reducing EU energy demand by 20% by 2020. However, predictions tend to overestimate savings by large percentages. The shortfall in savings can be attributed to incorrect predictive techniques, comfort takeback along with other behavioural and workmanship variables. Common predictive techniques related to heat loss tend to be based on the U-value of the building envelope. This paper presents the design of a more straightforward and compact version of the traditional Hot-Box apparatus (measures U-value) which instead determines the thermal resistance of samples of building envelope. U-value includes the need to …

Atomically Informed Nonlocal Semidiscrete Variational Peierls-Nabarro Model For Planar Core Dislocations, Guisen Liu, Xi Cheng, Jian Wang, Kaiguo Chen, Yao Shen

Department of Mechanical and Materials Engineering: Faculty Publications

Prediction of Peierls stress associated with dislocation glide is of fundamental concern in understanding and designing the plasticity and mechanical properties of crystalline materials. Here, we develop a nonlocal semi-discrete variational Peierls-Nabarro (SVPN) model by incorporating the nonlocal atomic interactions into the semi-discrete variational Peierls framework. The nonlocal kernel is simplified by limiting the nonlocal atomic interaction in the nearest neighbor region, and the nonlocal coefficient is directly computed from the dislocation core structure. Our model is capable of accurately predicting the displacement profile, and the Peierls stress, of planar-extended core dislocations in face-centered cubic structures. Our model could be …

Photoluminescence From Radiative Surface States And Excitons In Methylammonium Lead Bromide Perovskites, Dengyang Guo, Davide Bartesaghi, Haotong Wei, Eline M. Hutter, Jinsong Huang, Tom J. Savenije

Department of Mechanical and Materials Engineering: Faculty Publications

In view of its band gap of 2.2 eV and its stability, methylammonium lead bromide (MAPbBr₃) is a possible candidate to serve as a light absorber in a subcell of a multijunction solar cell. Using complementary temperature-dependent time-resolved microwave conductance (TRMC) and photoluminescence (TRPL) measurements, we demonstrate that the exciton yield increases with lower temperature at the expense of the charge carrier generation yield. The low-energy emission at around 580 nm in the cubic phase and the second broad emission peak at 622 nm in the orthorhombic phase originate from radiative recombination of charges trapped in defects with …

Helium Irradiation And Implantation Effects On The Structure Of Amorphous Silicon Oxycarbide, Qing Su, Shinsuke Inoue, Manabu Ishimaru, Jennifer A. Gigax, Tianyao Wang, Hepeng Ding, Michael J. Demkowicz, Lin Shao, Michael Nastasi

Department of Mechanical and Materials Engineering: Faculty Publications

Despite recent interest in amorphous ceramics for a variety of nuclear applications, many details of their structure before and after irradiation/implantation remain unknown. Here we investigated the short-range order of amorphous silicon oxycarbide (SiOC) alloys by using the atomic pair-distribution function (PDF) obtained from electron diffraction. The PDF results show that the structure of SiOC alloys are nearly unchanged after both irradiation up to 30 dpa and He implantation up to 113 at%. TEM characterization shows no sign of crystallization, He bubble or void formation, or segregation in all irradiated samples. Irradiation results in a decreased number of Si-O bonds …

Suspended Graphene-Based Gas Sensor With 1-Mw Energy Consumption, Jong-Hyun Kim, Qin Zhou, Jiyoung Chang

Department of Mechanical and Materials Engineering: Faculty Publications

This paper presents NH₃ sensing with ultra-low energy consumption for fast recovery and a graphene sheet based on a suspended microheater. Sensitivity and repeatability are important characteristics of functional gas sensors embedded in mobile devices. Moreover, low energy consumption is an essential requirement in flexible and stretchable mobile electronics due to their small dimension and fluctuating resistivity during mechanical behavior. In this paper, we introduce a graphene-based ultra-low power gas detection device with integration of a suspended silicon heater. Dramatic power reduction is enabled by a duty cycle while not sacrificing sensitivity. The new oscillation method of heating improves …

Vorticella: A Protozoan For Bio-Inspired Engineering, Sangjin Ryu, Rachel E. Pepper, Moeto Nagai, Danielle C. France

Department of Mechanical and Materials Engineering: Faculty Publications

In this review, we introduce Vorticella as a model biological micromachine for microscale engineering systems. Vorticella has two motile organelles: the oral cilia of the zooid and the contractile spasmoneme in the stalk. The oral cilia beat periodically, generating a water flow that translates food particles toward the animal at speeds in the order of 0.1–1 mm/s. The ciliary flow of Vorticella has been characterized by experimental measurement and theoretical modeling, and tested for flow control and mixing in microfluidic systems. The spasmoneme contracts in a few milliseconds, coiling the stalk and moving the zooid at 15–90 mm/s. Because the …

Investigation Of Electrical Defects Arising From Excessive Sidewall Force And Excessive Tensile Strain On Power Cables, Darren Mcconnon, Joseph Kearney, Tom Looby, James O'Shaughnessy

Conference papers

The study includes a comprehensive review of the existing literature and guidelines regarding the effects of sidewall force and tensile strain on power cables during installation. The most appropriate diagnostic test methods required to analyse these effects are also assessed. The results of tests and analysis of the existing literature are then combined in an attempt to determine a realistic basis for guidelines and recommendations relevant to cable installation forces.

A Review Of Control Methodologies For Dynamic Glazing, Eoin D. Mclean, Brian Norton, Derek Kearney, Philippe Lemarchand

Conference papers

With adaptive building façade technologies, a building envelope can provide a comfortable indoor environment under varying external conditions with minimal additional heating or cooling. The control strategy applied to the adaptation of the façade is a key determining factor in the successful integration of these technologies into a building. The building envelope plays a key role in regulating light, heat and mass transfer from the outdoor environment to the indoor. Dynamic glazing can be used to adjust the amount of solar radiation entering a building. The control strategies that ultimately determine the success of these switchable technologies to affect a …

Performance Evaluation And Characterization Of Encapsulated Calcium Nitrate For Self-Healing Concrete Applications, Jose Eduardo Milla

LSU Doctoral Dissertations

Self-healing concrete through microencapsulated calcium nitrate is a novel approach to enhance durability and decrease the costs associated with maintenance and repairs. However, to fully assess the potential of this technology, there are many questions to be answered, ranging from identifying the microcapsule properties that are successfully carry the healing agent, to the effect of the microcapsule size, concentration (by weight of cement), and morphology have on the intrinsic concrete material properties and self-healing potential. Hence, the objectives of this study were to: (a) Develop a microencapsulation procedure for calcium nitrate as the healing agent; (b) Measure the short-term healing …

Comparison Of Extruder Systems For 3d Printer Filament Fabrication, Adriana Ramirez

Open Access Theses & Dissertations

Additive Manufacturing (AM) has grown in popularity over the past thirty years, due to its versatility, short design to product cycle, and capability to fabricate complex geometries, which cannot otherwise be produced. There exist several platforms that are able to print objects composed of different materials, making this technology significant in different fields such as: automotive, aerospace, medical, electronics, amongst others. Though several types of AM technologies are available, the expiration of the patents on fused deposition modeling (FDM) in 2009 has led to a widespread use of this platform in academia and home use settings.

Widespread use of FDM-type …

Material Behavior Of Window 7 Carrier Panel Tiles And Thermal Pane Fragments Recovered From The Space Shuttle Columbia, Brenda Roseanne Arellano

Open Access Theses & Dissertations

Since the end of the space shuttle program, a new generation spacecraft has been developed to transport humans back into space. NASAâ??s Orion will carry a crew beyond low-earth orbit and the exploration of Mars may be possible in the future. Space safety becomes significant with human spaceflight and the risks are high. However, aerospace materials may provide opportunities to prevent future disasters. When the space shuttle Columbia disintegrated during re-entry in 2001, thousands of debris were collected for analysis. In contrast, when the Challenger space shuttle broke apart in 1986, all shuttle debris were buried. These tragic disasters are …

The Interplay Between Grain Size And Austenite Stability On Deformation Behavior Of High Strength-High Ductility Combination Nanostructured Stainless Steel, Venkata Sai Ananth Challa

Open Access Theses & Dissertations

The concept of phase reversion involving severe cold deformation of metastable austenite to generate strain-induced martensite, followed by temperature-time annealing sequence, was used to obtain varying grain size from nanograined/ultrafine-grained (NG/UFG) to coarse-grained (CG) regime. This concept was used to obtain â??high strength-high ductilityâ?? combination in nano/ultrafine-grained (NG/UFG) austenitic stainless steel. Using this concept, the objective of the study is to elucidate the dependence of grain size on deformation mechanisms and deformation-induced microstructural changes. The objective was accomplished by combining depth-sensing nanoindentation experiments conducted at various strain rates, and interrupted tensile testing at various strain and post-mortem analyses of deformed …

Dft Study Of Adsorption Of Trimetallic Endohedral Fullerenes On Graphene, Nakul Nitin Karle

Open Access Theses & Dissertations

A density functional theory (DFT) study on the geometric and electronic structure of C60 and Sc3N@C80 along with their adsorption on pristine single layer graphene (SLG) is presented. C60 is found to adsorb in two nearly degenerate configurations: (i) with a pentagon facing the SLG, which is the most stable one, and (ii) with a hexagon facing the SLG in a face-to-face perfect alignment, rarely common in Ï?â??Ï? interactions, 0.06 eV higher in energy. The calculated binding energy of 0.76 eV, which includes dispersion effects, is in good agreement with previous theoretical and experimental reports. On the contrary, Sc3N@C80 adsorption …

Analytical Strip Method For Thin Cylindrical Shells, John T. Perkins

Theses and Dissertations--Civil Engineering

The Analytical Strip Method (ASM) for the analysis of thin cylindrical shells is presented in this dissertation. The system of three governing differential equations for the cylindrical shell are reduced to a single eighth order partial differential equation (PDE) in terms of a potential function. The PDE is solved as a single series form of the potential function, from which the displacement and force quantities are determined. The solution is applicable to isotropic, generally orthotropic, and laminated shells. Cylinders may have simply supported edges, clamped edges, free edges, or edges supported by isotropic beams. The cylindrical shell can be stiffened …

Redox-Active Solid State Materials And Its Biomedical And Biosensing Applications, Ankur Gupta

Electronic Theses and Dissertations

Reactive oxygen species (ROS) are byproducts of physiological processes in human body, and strengthened production of ROS is known to cause acute conditions such as inflammation, aging, Alzheimer's disease, melanoma and ovarian cancer, fibrosis and multiple sclerosis. Therefore, early detection of ROS at nanomolar concentration (at cellular level) and developing more potent antioxidants is essential for regular health monitoring. As an example, ROS are also responsible for inflammation reactions at orthopedic implants-tissue interface triggered by wear debris. Inflammation induced by ROS results in revision surgery. Coatings of redox-active materials exhibiting antioxidant properties on implants have potential to mitigate the inflammation …

Developing An Insider Threat Experimental Environment, Eric Ortiz

Electronic Theses and Dissertations

Simulated, 3D gaming environments have been used for a wide-range of applications including training, entertainment, and experimentation in an assortment of domains for some time. This can be attributed to their unique ability to emulate multifaceted situations that may be difficult to control, while affording participants the opportunity to operate in a relatively safe environment. In cybersecurity research, investigation of insider threat behavior is an endeavor that has received little attention in terms of available environments and resources for experimental manipulation. This research effort aimed to close this gap. A simulated, 3D gaming environment and accompanying scenarios were developed for …

Frontal Crash Analysis Of A Conformable Cng Tank Using Finite Element Analysis, Datta Sandesh Manjunath

Dissertations, Master's Theses and Master's Reports

The purpose of this study is to computationally model and analyze a Conformable Compressed Natural Gas (CNG) fuel tank for frontal crashes using Finite Element Analysis. Researchers have developed a CNG fuel tank, which is conformable, non-conventional and non-cylindrical. This tank increases cost efficiency, volumetric efficiency and cargo efficiency in CNG vehicle applications. A lightweight pickup truck (2015 Chevrolet Silverado) has been used to integrate the CNG tanks and field-testing has been conducted to demonstrate the application.

The report mainly focuses on the effective finite element modeling of the chassis, brackets and tanks using HYPERMESH and RADIOSS. The frontal crash …

Easily Verifiable Controller Design With Application To Automotive Powertrains, Mohammad Reza Amini

Dissertations, Master's Theses and Master's Reports

Bridging the gap between designed and implemented model-based controllers is a major challenge in the design cycle of industrial controllers. This gap is mainly created due to (i) digital implementation of controller software that introduces sampling and quantization imprecisions via analog-to-digital conversion (ADC), and (ii) uncertainties in the modeled plant’s dynamics, which directly propagate through the controller structure. The failure to identify and handle these implementation and model uncertainties results in undesirable controller performance and costly iterative loops for completing the controller verification and validation (V&V) process.

This PhD dissertation develops a novel theoretical framework to design controllers that are …

Reuse And Recycling Drill Cuttings In Concrete Applications, Maziar Foroutan

LSU Master's Theses

Drill cutting (DC) is a major waste produced during petroleum extraction, which could present a major source of contamination to soil and groundwater, if not disposed of properly. The objective of this study aims to test the hypothesis that drill cuttings can be incorporated as an aggregate in the production of concrete, and is suitable for use in controlled, low-strength material (CLSM) for non-structural applications. To achieve this objective, the physical and consensus properties of drill cuttings were characterized. Concrete mixtures were designed for CLSM applications with and without drill cuttings sampled from two sources. Prepared concrete mixes were then …

Determination Of Forming Ability Of High Pressure Die Casting For Zr-Based Metallic Glass, Lehua Liu, Jiang Ma, Chunyan Yu, Xiusong Huang, Liangju He, Laichang Zhang, Peijie Li, Zhiyuan Liu

Research outputs 2014 to 2021

Large-sized industrial grade Zr₅₅Cu₃₀Ni₅Al₁₀ bulk metallic glass (BMG) was fabricated by a two-step arc-melting process and adding a trace of rare earth yttrium elements. A model to calculate critical cooling rate for forming BMG was established by considering the effect of pressure. Based on the model, the most important indicator, namely the critical size of forming BMG, for design and fabrication of BMG components by high pressure die casting (HPDC) is determined in consideration of different processing parameters, including the pressure and casting temperature. Theoretical calculation and numerical simulation indicated that increasing applied …

Fretting Wear Behaviors Of Aluminum Cable Steel Reinforced (Acsr) Conductors In High-Voltage Transmission Line, Xingchi Ma, Lei Gao, Junxi Zhang, Laichang Zhang

Research outputs 2014 to 2021

This work reports the fretting wear behavior of aluminum cable steel reinforced (ACSR) conductors for use in high-voltage transmission line. Fretting wear tests of Al wires were conducted on a servo-controlled fatigue testing machine with self-made assistant apparatus, and their fretting process characteristics, friction force, wear damage, and wear surface morphology were detailed analyzed. The results show that the running regime of Al wires changes from a gross slip regime to a mixed regime more quickly as increasing contact load. With increasing amplitudes, gross slip regimes are more dominant under contact loads of lower than 30 N. The maximum friction …